Thermal circuit-breaker



J. F. LAMB.

- THERMAL CIRCUIT-BREAKER.

APPLICATION FILED JULY 20, l9l7.

1,377,257. Pat nt d May 1041921.

- I IN VENTQR. Josqvl; 1E Lamb:

. ATTORNEY.

To all whom it may concerm advantage.

I UNITED ,STATES PATENT OFFICE.

JOSEPH F. LAMB, OF NEW BRITAIN, CONNECTICUT, ASSIGNOR TO L ANDERS, FRAR'Y &

CLARK, OF NEW BRITAIN, CONNECTICUT, A CORPORATION OF CONNECTICUT.

, Application filed July 20,

Be it known that I, JOSEPH F. LAMB, a citizen of the United States, and a resident of New Britain, in the county of Hartford, State of Connecticutfhave invented certain new and useful Improvements in a Thermal Circuit-Breaker, of which the following is a specification.

This invention relates particularly to means for cutting off the current from a utensil as it approaches a dangerous degree of heat, the object being to protect a device of this sort having features of novelty and In the drawings Figure 1. is a side view of the device.

. Fig. 2. is a plan view of the same.

Fig. 3 is a transverse section in line 3-3 Fi 1.

Fig. 4. is a side view with the parts shown in the position assumed when a circuit is broken. p

Fig. 5 is a detail view showing the circuit closer and the spring contact blades in the position assumed just after release of the circuit breaker and just before its disengage ment from'the contact blades.

Referring to the drawings :-.-Where the invention is illustrated as embodied in a sad iron, 0:, denotes the iron, 6, b, the terminal posts, 0, denotes one terminal wire from the wire.

heatin element and (Z, the other terminal y reference to Fig. 3.it will be seen that the terminal wire 0, is connected with the post 6, and that the other terminal post 6 is connected with one member, 2, of a pair of spring blades, the other member, 3, of

V which is connected through the binding the blades 2,

post,4, with the other terminal wire 03, from the heating element.

The circuit between the terminal posts and the heating element is thus broken at In accordance with my invention acircuit closer is provided to bridge the gap between the blades 2, 3, spring supported so that it is normally out of operative position but held down; in operative position by a thermally controlled member, thus providing an automatically operating "circuit breaker for the iron, operative upon a rise in temperature without interference with the usual connection plug, which is en aged with the terminal posts'b, b'. One orm of device for ac complishing these" objects and which has THERMAL CIRCUIT-BREAKER.

1917. Serial no. 121,839.. 1

. been found to be. sufficient, is illustrated in the drawings and will now be described.

It comprises a spring, 15-, with one end mounted on a part of the iron, its opposite end being provided with a bracket, 11:, the

" arms of which have elongated slots, 12, in

which are mounted studs, 13, of a metal roller, 14:, which, when the spring is pressed down, enters between the blades 2, 3, and

closes the circuit. The elongated slots 12 enable the. spring to have a movement independently of the metal roller and especially when the latter is held by the blades 2 and 3. As a result the initial movement of the spring independentlyof the roller will cause a blow tobe delivered upon the studs 13 as of the thermostatic device somewhat more delicate. The interengaging parts of the thermostatic device and the spring 15 are preferably similarly inclined and hardened which also renders the action of'engagement and disengagement more delicate by permitting it to be accomplished within a comparatively slight range of movement of the thermostatic member.

As illustrated the spring is provided with a plate, 22, having an inclined surface cooperating with the tapered end, 24, of apin,

Specification of Letters Patent. Patented May 10, 1921. l

23, which is adjustable throu h the end of the thermostatic member. y the use of this adjustable pin, the device can be set to release at difierent degrees of temperature. This arrangement of the inclined surfaceson the plate and end. of the pin causes the plate to have a cam action on the pin under the force of thesprin to move upwardly, with a result that the Torce of the spring is utilized to aid in the disengagement of the parts. I 20, indicates a plate which is secured to a part of the iron and upon which is mounted the thermostatic member and the spring support for the circuit closer. By thus assembling these parts they can be tested and properly set before they are assembled with standard test which may be established.

ll do not desire it to beunderstood that a this invention is limited to the use of the thermostatic member since other heat controlled devices, such, for instance, as fusible plugs, might be utilized. 1 am also aware that the structure here illustrated and described is susceptible to modification in various parts and I do not wish anything herein contained to be considered as a limitation either as to the form and arrangement of the parts in detail or as to the manner or place of use of the device.

ll claim as my invention 1. A circuit breaker for an electrically heated utensil comprising a spring actuated circuit closer provided with a part having an inclined surface, and a thermostatic bar providedwith an adjustable screw having a tapering end engaging the inclined surface on said part.

-2. A thermal ci rupting the circuit in an electrically heated utensil 'when said utensil becomes overheated, comprising a plate removably semally controlled member cotiperating with 'said circuit closer, adjustable interengaging means between said circuit -closer and thermally controlled member, and a plate removably secured to the utensil and to which said circuit closer and thermally controlled mem- .ber are fixed to permit adjustment of said circuit breaker prior to the attachment of said plate to the utensil.

4. A thermal circuit breaker for interrupting the circuit in an electrically heated utensil when said utensil becomes overheated, comprising a spring, a thermally controlled member cooperating therewith,

cooperating parts on said spring and memher, a circuit closer carried by said spring,

and a plate removably secured to said utensil and to which said sprlng and thermally I controlled member are fixed to permit adjustment of thecircuit breaker prior to the attachment of the plate to the utensil.

5. In a circuit breaker for an electrically rcuit breaker, for inter-.

heated utensil provided with a normally open circuit, a circuit closed therefor, comprising a bracket having elongated slots therein, a roller provided with studs located and movable in said slots whereby a blow may be imparted to aid in the separation of the roller from a member holding the same, a spring on which said bracket is mounted, and a thermally-controlled member for holding said spring with the circuit closer in operative position.

6.- ln a circuit breaker for electrically heated utensils having a normally open circuit, a spring secured at one of its ends, a bracket on the free end of said spring, and a circuit closing member carried by said bracket and having 'a limited movement relative to and independently of said spring I and bracket whereby when said spring is released a blow will. be delivered to said circuit closing member to aid in the separation of the parts.

7. In a thermal circuit breaker for electrically heated utensils having a normally open circuit, a pair of spring blades, a circuit closing member adapted to bridge the gap between said blades and to be gripped by the blades, and a spring supporting said circuit closing member, said spring having a limited movement relative to saidcircuit closing member whereby a blow may be imparted to the,circuit closing member to aid in the separation thereof from said blades. 8. In a thermal circuit breaker for elec-' trically heated utensils having a normally open circuit, a spring unresponsive to thermal changes and secured at one of its ends,-

a circuit closing member carried by the free end of said spring, a thermostatic bar extending longitudinally of and mov able in a plane at right angles to the path of said spring, and cooperating surfaces on said spring and bar.

9. A thermal circuit breaker, for interrupting the circuit in an electrically heated I utensil when said utensil becomes overheated, COIIIPI'ISIHg a c1rcu1t closing member, a spring, and a connection between said circuit closing member and spring permitting limited movement of said spring rela tive to said circuit closing member whereby when said spring is released a blow may be delivered to said circuit closing member to aid in theseparation of the parts.

JQSEPH t. LAMB.

. Vfitnesses':

' Brass CLARK,

Gtrrron' "W. 

